diff options
Diffstat (limited to 'fs/fscache/fsdef.c')
| -rw-r--r-- | fs/fscache/fsdef.c | 145 |
1 files changed, 0 insertions, 145 deletions
diff --git a/fs/fscache/fsdef.c b/fs/fscache/fsdef.c deleted file mode 100644 index 10a2ade0bdf8..000000000000 --- a/fs/fscache/fsdef.c +++ /dev/null @@ -1,145 +0,0 @@ -/* Filesystem index definition - * - * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License - * as published by the Free Software Foundation; either version - * 2 of the License, or (at your option) any later version. - */ - -#define FSCACHE_DEBUG_LEVEL CACHE -#include <linux/module.h> -#include "internal.h" - -static uint16_t fscache_fsdef_netfs_get_key(const void *cookie_netfs_data, - void *buffer, uint16_t bufmax); - -static uint16_t fscache_fsdef_netfs_get_aux(const void *cookie_netfs_data, - void *buffer, uint16_t bufmax); - -static -enum fscache_checkaux fscache_fsdef_netfs_check_aux(void *cookie_netfs_data, - const void *data, - uint16_t datalen); - -/* - * The root index is owned by FS-Cache itself. - * - * When a netfs requests caching facilities, FS-Cache will, if one doesn't - * already exist, create an entry in the root index with the key being the name - * of the netfs ("AFS" for example), and the auxiliary data holding the index - * structure version supplied by the netfs: - * - * FSDEF - * | - * +-----------+ - * | | - * NFS AFS - * [v=1] [v=1] - * - * If an entry with the appropriate name does already exist, the version is - * compared. If the version is different, the entire subtree from that entry - * will be discarded and a new entry created. - * - * The new entry will be an index, and a cookie referring to it will be passed - * to the netfs. This is then the root handle by which the netfs accesses the - * cache. It can create whatever objects it likes in that index, including - * further indices. - */ -static struct fscache_cookie_def fscache_fsdef_index_def = { - .name = ".FS-Cache", - .type = FSCACHE_COOKIE_TYPE_INDEX, -}; - -struct fscache_cookie fscache_fsdef_index = { - .usage = ATOMIC_INIT(1), - .n_active = ATOMIC_INIT(1), - .lock = __SPIN_LOCK_UNLOCKED(fscache_fsdef_index.lock), - .backing_objects = HLIST_HEAD_INIT, - .def = &fscache_fsdef_index_def, -}; -EXPORT_SYMBOL(fscache_fsdef_index); - -/* - * Definition of an entry in the root index. Each entry is an index, keyed to - * a specific netfs and only applicable to a particular version of the index - * structure used by that netfs. - */ -struct fscache_cookie_def fscache_fsdef_netfs_def = { - .name = "FSDEF.netfs", - .type = FSCACHE_COOKIE_TYPE_INDEX, - .get_key = fscache_fsdef_netfs_get_key, - .get_aux = fscache_fsdef_netfs_get_aux, - .check_aux = fscache_fsdef_netfs_check_aux, -}; - -/* - * get the key data for an FSDEF index record - this is the name of the netfs - * for which this entry is created - */ -static uint16_t fscache_fsdef_netfs_get_key(const void *cookie_netfs_data, - void *buffer, uint16_t bufmax) -{ - const struct fscache_netfs *netfs = cookie_netfs_data; - unsigned klen; - - _enter("{%s.%u},", netfs->name, netfs->version); - - klen = strlen(netfs->name); - if (klen > bufmax) - return 0; - - memcpy(buffer, netfs->name, klen); - return klen; -} - -/* - * get the auxiliary data for an FSDEF index record - this is the index - * structure version number of the netfs for which this version is created - */ -static uint16_t fscache_fsdef_netfs_get_aux(const void *cookie_netfs_data, - void *buffer, uint16_t bufmax) -{ - const struct fscache_netfs *netfs = cookie_netfs_data; - unsigned dlen; - - _enter("{%s.%u},", netfs->name, netfs->version); - - dlen = sizeof(uint32_t); - if (dlen > bufmax) - return 0; - - memcpy(buffer, &netfs->version, dlen); - return dlen; -} - -/* - * check that the index structure version number stored in the auxiliary data - * matches the one the netfs gave us - */ -static enum fscache_checkaux fscache_fsdef_netfs_check_aux( - void *cookie_netfs_data, - const void *data, - uint16_t datalen) -{ - struct fscache_netfs *netfs = cookie_netfs_data; - uint32_t version; - - _enter("{%s},,%hu", netfs->name, datalen); - - if (datalen != sizeof(version)) { - _leave(" = OBSOLETE [dl=%d v=%zu]", datalen, sizeof(version)); - return FSCACHE_CHECKAUX_OBSOLETE; - } - - memcpy(&version, data, sizeof(version)); - if (version != netfs->version) { - _leave(" = OBSOLETE [ver=%x net=%x]", version, netfs->version); - return FSCACHE_CHECKAUX_OBSOLETE; - } - - _leave(" = OKAY"); - return FSCACHE_CHECKAUX_OKAY; -} |
